If I am the only person here who bought non-functional AMD CPUs - I envy you guys. Maybe it's because I now assemble maybe one machine weekly, and did up to 10 several years ago... Back in 1993 making a top PC brought us $500 for two persons...
In fact the only brand of CPUs that I have bought were AMDs

Overclocking is not an issue. At least when I make PCs for my clients. But on my own machines I usually squeeze every megahertz. But it's more like sport, not expecting any marvelous results. You'll laugh, but I am satisfied with Athlon-XP1600 both at work and at home. Funny but both chips are not oberclockable, I tried everything, including voltage and different multipliers

For myself - I'll probably never buy an Intel system. For clients - never buy AMD.
I didn't see any incompatibility of AMD CPUs, no bugs except in case it refuses to work from the very beginnng, at least at notma temperature and frequency.
Maybe we'll have an order from our scientists for 64bit AMD, but it still seems to us that a dual-CPU system will cost as 5-6 ordinary P4 in a cluster on gigabit ethernet, and that guys run cluster-friendly tasks. Anyway, could be interesting to do something like that.
We dismantled Convex C2 several months ago... As our scientists said it was faster then modern systems they had. But it costed millions in late-80s, when Academy could afford it.